question on vgextend

[Wade Adams]

Basicly I have 2 800 gig vol's and need to create a alt path for these. Problem is I only have 2 free Physical extents. Does anyone know a formular to figure out how many I will need ?

thx

[Wade Adams]

In case it matters, this is on HPUX 11.

[Tobias Hartlieb]

HI,

first of all, you might get a more qualified answere in the HP-UX area, because this is about LVM.
Anyway, if you just want to create an alternate link (i.e. accessing the same physical disks via an alternate route), you just do an vgextend /dev/VGNAME /dev/dsk/DEVICE_FILE_OF_NEW_DISK_ROUTE
There are no more PE used, because the information is stored in the LVM tab and the LVM header of the disks, which has been created already initally by doing pvcreate.

[Santosh Nair_1]

If by alt path, you mean that you want to access the same phyiscal disk via a different controller, then this should use up no additional PEs. You just have to do a vgextend /dev// and the new disk will be added to the VG. You can verify by doing a vgdisplay -v ...it should list both disks in the VG marking one as an alternate link. Hope this helps.

-Santosh

[Ron Cornwell]

Please explain more... I understand you have (2) 800GB VG's. What confuses me is the inclusion of the PE remark in your question. Are you looking to create alternate links to you PV's in the OS?? Are you trying to set the alternate boot path to a boot disk ??

Ron

[Wade Adams]

I have 2 paths (host adapters) to our raid storage. I beleive the volume was created with 32 (meg?)extent(s). vgdisplay shows 2 physical extents free.
When I run >vgextend /dev/vg01 /dev/dsk/c7t0d0 I get a error

Too many physical extents for volume group. Can not add physical volume to Volume group. LVM_MAXPXS:65535

This is a new setup and there is no data currently.

I did not create the volumes but beleive the solution is to recreate the volume with a larger extent size. I'm just trying to figure out what that value should be.

Thx

[Ron Cornwell]

What are you trying to do? Mirror the lvols? create redundant paths? or provide a little load balancing?

[Patrick Wallek]

I found a couple of TKB documents that you can check.

TKB Doc ID: 1100364494
http://us-support.external.hp.com/cki/bin/doc.pl/sid=4508e40d13dfeb14f4/screen=ckiDisplayDocument?docId=200000053080181

TKB Doc ID: 5003407064
http://us-support.external.hp.com/cki/bin/doc.pl/sid=4508e40d13dfeb14f4/screen=ckiDisplayDocument?docId=200000041143098

Patch PHCO_18485 is referenced in the last link as the solution. PHCO_18485 has been superseded and the latest patch is PHCO_24437
http://us-support.external.hp.com/wpsl/bin/doc.pl/screen=wpslDisplayPatch/sid=eff5c10506287da52f?PACH_NAM=PHCO_24437

[Wade Adams]

set the redundant path.

[Ron Cornwell]

Here is an article that will help http://us-support3.external.hp.com/cki/bin/doc.pl/sid=c02007fe0589e29784/screen=ckiDisplayDocument?docId=200000048319669 . Let me know if you need more help.

-Ron

[harry d brown jr]

Can you post :

vgdisplay -v vg01

for us?

thanks,

live free or die
harry

[Sridhar Bhaskarla]

Wade,

If it is a 10.20 system, then it's a problem and you need to install the patch PHCO_23437.

//start (Part of Patch description)

PHCO_17118:
vgextend does not allow extension of volume group
more than 65535(LVM_MAXPXS), which is the value for a
physical volume. The actual limit for volume group
should be 65535 * 255 (LVM_MAXPXS * LVM_MAXPVS).

//End

-Sri

[Sridhar Bhaskarla]

Oops.. Didn't read your second message. Yours is a 11.0 system. Then the above is not applicable. But still I suggest to install the lastest LVM commands patch PHCO_24437 and see if it fixes the problem. I didn't read the patch description.

Now as a work around, when you get sometime, probably you can do a vgexport and import the volume group back. I suppose the problem is only with the command that is doing a wrong check. So, vgimport should be able to get the other disk also back.

#vgchange -a n vgxx
#vgexport -v -s -m /tmp/vgxx.map vgxx
#mkdir /dev/vgxx
#mknod /dev/vgxx/group c 64 0x0?0000
#vgimport -v -s -m /tmp/vgxx.map vgxx

Do a vgdisplay and see if you got the alternate link.

-Sri

[Ron Cornwell]

I have found the answer in at a cumulative patch for LVM http://us-support3.external.hp.com/wpsl/bin/doc.pl/screen=wpslDisplayPatch/sid=9f391b6e12655d0e96?PATCH_PATH=/superseded_patches/hp-ux_patches/s700_800/11.X/PHCO_23791&HW=s800&OS=11.00

[Nodoz]

Kewl, I didn't have access to that area but it would seem the patch in 5003407064 is what we need. I'll try it and let you all know. Thx for the help.